By default, Yandex.Mail uses a two-panel interface. The message preview is displayed on a separate page to the right from the list of folders. Links to other Yandex services are located above the list of messages.
You will be able to change the appearance of the two-panel interface and make it more compact. To do this, click above the list of folders.
To revert to the default interface, click above the list of folders.
If you want to both view the list of messages and the message content, you can switch to the three-panel interface and open messages to the right or below the list of messages. To do this:
The three-panel interface is intended for more convenient work with messages and provides a neater visual appearance than the default. This interface also uses another message selection method and always groups messages by theme and sender. Links to other Yandex services are available in the bottom left corner.
To switch back to the two-panel interface, go to Settings → Visual appearance and in the Open messages section, click On a new page.
The light interface is intended only for basic operations with messages, such as creating, reading, viewing attachments, labeling messages, etc. Themes are not supported, and there is no way to configure custom buttons or mail processing rules.
You can select between a plain and thematic appearance for Yandex.Mail. To apply a theme, click in the upper right corner and then left-click the theme you want. To view all available themes, click All themes in the bottom right corner of the drop-down menu.